The pavers you see on the surface are only part of the system. What lies beneath matters just as much. Maybe more.
A paver installation is like an iceberg. The visible part gets all the attention, but the hidden layers do the real work. When those layers are done right, your pavers will stay level and stable for decades. When they’re rushed or skipped, problems show up within a few years.
This guide explains each layer of a proper paver system. You’ll learn what goes into professional installation and why cutting corners always costs more in the long run.
The Layers of a Paver System
A complete paver installation has five main layers, starting from the bottom:
- Subgrade (the existing soil)
- Base material (crushed rock)
- Bedding layer (sand)
- Pavers (the surface you see)
- Joint material (sand between pavers)
Each layer has a specific job. Skip one, and the whole system can fail.
Layer 1: Subgrade Preparation
The subgrade is the natural soil beneath your project. Before anything else goes in, this soil needs attention.
Why It Matters
Soil moves. It expands when wet and shrinks when dry. Clay soils are especially problematic in Southern California. If you place pavers on unprepared soil, that movement transfers to the surface. You get dips, bumps, and uneven pavers.
What Proper Preparation Looks Like
First, the area is excavated to the correct depth. This depth depends on what the pavers will support. A patio might need 7 to 8 inches of total depth. A driveway that handles vehicles needs 10 to 12 inches or more.
Next, the subgrade is compacted. A plate compactor or roller presses the soil down to create a firm foundation. Any soft spots are addressed. If the soil is too loose or unstable, it may need to be removed and replaced with better material.
The subgrade should also be graded for drainage. Water needs to flow away from structures, not pool under your pavers.
What Happens When It’s Skipped
Installers who rush this step often regret it. Settling happens within the first year or two. You’ll see dips where vehicles park, low spots that collect water, and pavers that shift out of place.
Fixing a failed subgrade means removing all the pavers, digging out the base, and starting over. It costs far more than doing it right the first time.
Layer 2: Base Material
The base layer sits on top of the subgrade. It’s usually made of crushed rock or gravel, often called “road base” or “Class II base.”
Why It Matters
The base layer does three critical jobs:
Load distribution: It spreads weight across a wider area. When a car drives over your driveway, the base prevents that weight from concentrating in one spot and pushing down into the soil.
Drainage: Crushed rock has gaps between the pieces. Water can drain through instead of sitting under your pavers.
Stability: A properly compacted base doesn’t shift or settle. It creates a solid platform for everything above.
What Proper Installation Looks Like
Base material is installed in layers, or “lifts.” Each lift is typically 2 to 3 inches deep. After each lift is spread, it gets compacted before the next layer goes on.
This process takes time. You can’t dump 6 inches of gravel and compact it once. The bottom won’t get compressed properly. Installing in lifts and compacting each one creates a base that’s solid all the way through.
For a standard patio, the base is usually 4 to 6 inches thick after compaction. For driveways and areas with vehicle traffic, 6 to 8 inches is common. Heavy-use areas may need even more.
What Happens When It’s Skipped or Rushed
A thin base can’t distribute weight effectively. Heavy loads push through and deform the subgrade below.
A base that’s not compacted in lifts will settle unevenly. You’ll see ruts in driveways and wavy surfaces on patios.
Some installers use the wrong material to save money. Round pea gravel, for example, doesn’t lock together like angular crushed rock. It shifts under pressure instead of staying put.
Layer 3: Bedding Sand
On top of the compacted base goes a thin layer of sand. This is called the bedding layer or screed layer.
Why It Matters
The bedding sand serves two purposes:
Leveling: Even a well-compacted base isn’t perfectly smooth. The sand layer lets installers create a precise, level surface for the pavers.
Cushioning: Sand allows pavers to seat properly during final compaction. It fills tiny gaps between the paver and the base.
What Proper Installation Looks Like
Bedding sand is spread to a uniform depth, usually about 1 inch. It’s screeded (smoothed with a straight edge) to create a flat plane.
The sand should be slightly damp, not dry or soaking wet. Damp sand holds its shape better during paver placement.
Installers use coarse, sharp sand, not fine play sand or beach sand. The angular grains lock together better than round grains.
What Happens When It’s Done Wrong
Too much sand causes problems. If the bedding layer is 2 or 3 inches thick, pavers will settle unevenly over time. The industry standard is 1 inch for good reason.
The wrong type of sand won’t hold pavers in place. Fine sand or round sand allows movement and leads to shifting pavers.
Walking on screeded sand before placing pavers creates footprints and dips. Professional crews work systematically to avoid disturbing the bedding layer.
Layer 4: Paver Installation
Now comes the visible part. Pavers are placed on the bedding sand in the chosen pattern.
Why It Matters
Paver placement affects both appearance and performance. A tight, consistent layout looks professional and resists shifting.
What Proper Installation Looks Like
Pavers are placed by hand, starting from one corner or edge. Installers work outward to avoid stepping on placed pavers.
Joints between pavers are kept consistent, usually 1/8 to 1/4 inch. Some pavers have built-in spacer bars that maintain proper spacing automatically.
When pavers reach edges or curves, they need to be cut. Professional crews use wet saws for clean, precise cuts. The cut pieces should be at least half the size of a full paver. Tiny slivers look bad and can work loose over time.
After all pavers are placed, the surface gets compacted with a plate compactor. This seats the pavers into the bedding sand and levels the surface. A protective pad on the compactor prevents scratching.
What Happens When It’s Done Wrong
Inconsistent joints look sloppy and allow more movement between pavers.
Poor cutting leaves rough edges and weak pieces that break or shift.
Skipping the final compaction leaves pavers sitting high. They’ll settle unevenly under use instead of settling uniformly during installation.
Layer 5: Joint Sand and Edge Restraints
Two more elements complete the system: the sand between pavers and the borders that hold everything in place.
Joint Sand
After compaction, sand is swept into the joints between pavers. Most professional installations use polymeric sand, which contains additives that harden when wet.
Polymeric sand does several things:
- Locks pavers together so they can’t shift sideways
- Resists washout from rain and irrigation
- Prevents weeds from growing in the joints
- Keeps insects from nesting between pavers
Regular sand works too, but it washes out more easily and doesn’t prevent weeds as well.
The sand is swept in, the surface is compacted again, more sand is added, and then water activates the polymers. It takes 24 to 48 hours to fully set.
Edge Restraints
Edge restraints are borders installed around the perimeter of the paver area. They keep the outside pavers from creeping outward over time.
Without edge restraints, the whole system slowly spreads. Joints widen, pavers loosen, and the surface becomes uneven.
Edge restraints can be:
- Plastic paver edging (most common)
- Aluminum edging (stronger, more durable)
- Concrete borders
- Existing structures like walls or foundations
They’re secured with spikes driven into the base material. The restraint should be hidden just below the top of the pavers.
What Happens When These Are Skipped
No polymeric sand means weeds, insects, and washout. You’ll spend more time on maintenance and repairs.
No edge restraints mean spreading pavers. The edges will start to wander within a year or two, especially in high-traffic areas.
Why This All Matters
If you’re comparing bids for a paver project, the difference often comes down to these hidden layers. A low bid might mean:
- Thinner base material
- No compaction in lifts
- Regular sand instead of polymeric sand
- Skipped or cheap edge restraints
These shortcuts don’t show up on day one. Your new patio or driveway will look great. But within a few years, the problems appear. And fixing them means starting over.
Professional installers who follow industry standards charge more because they do more. The work you can’t see is what makes your investment last.
Questions About Your Project?
Understanding what goes into a quality installation helps you make better decisions. If you’re planning a paver project and want to know what proper preparation looks like for your specific site, reach out to our team. We’ll walk you through the process and explain exactly what your project needs.
Not sure where to start? Our guide on paver basics and terminology covers the fundamentals of materials and types.